An overview of alginates as flame-retardant materials: Pyrolysis behaviors, flame retardancy, and applications

Alginates, a kind of naturally occurring polysaccharides, have been exploited for functional materials owing to their versatility, sustainability, nontoxicity, and relatively low cost. Inherent flame retardancy is one of the most attractive features of alginates, as it enables the high-value-added utilization of alginates for eco-friendly flameretardant materials. Now, the influence of metal ions on the flame retardancy and pyrolysis behaviors of alginates has been systematically studied; besides, the applications of alginates for flame-retardant materials have been greatly developed, such as for preparing flame-retardant fibers, fabrics, aerogel composites, and foams, as well as serving as a component or modifier of functional coatings, hybrids, and additives. This review will give an overview of the recent progress and the prospects of using alginates in flame-retardant fields, which can guide the design of bio-based flame retardants and benefit the further development of more diverse applications of alginates.